Cable operators have widely deployed high-speed data services on cable television systems. These data services include a cable modem that allows a computer to communicate over an ordinary cable TV network Hybrid Fiber Coax (HFC) cable. A Cable Modem Termination System (CMTS) connects the cable TV network to a data network, such as the Internet. The Data Over Cable Service Interface Specification (DOCSIS) is one of the cable modem standards used for transferring data over the cable TV network. Increasing demand for cable data services requires additional CMTS processing capacity. This can be prohibitively expensive since each CMTS provides routing, DOCSIS Media Access Control (MAC) processing, downstream signal modulation, and upstream signal demodulation. A conventional CMTS architecture does not scale well since any one of the separate components in the CMTS can limit processing capacity and only a limited number of DOCSIS packet processing devices and physical interfaces can be located in the same CMTS chassis.
Different cable networks may also have different processing requirements. For example, one cable network may require substantially more upstream data services than other cable networks. However, it is difficult to customize CMTS architectures for these different data services requirements. It is also expensive to provide redundancy in current CMTS architectures since each backup CMTS includes DOCSIS MAC processors, downstream cable modulators and upstream signal demodulators.